﻿using System;
using System.Data;
using System.Xml;
using System.Data.SqlClient;
using System.Collections;
using System.Configuration;

namespace Randao.Core
{
	/// <summary> 
	/// SqlServer数据访问帮助类 
	/// </summary> 
	public sealed class SqlHelper
	{
		#region 私有构造函数和方法

		private SqlHelper() { }

		/// <summary> 
		/// 将SqlParameter参数数组(参数值)分配给SqlCommand命令. 
		/// 这个方法将给任何一个参数分配DBNull.Value; 
		/// 该操作将阻止默认值的使用. 
		/// </summary> 
		/// <param name="command">命令名</param> 
		/// <param name="commandParameters">SqlParameters数组</param> 
		private static void AttachParameters(SqlCommand command, SqlParameter[] commandParameters)
		{
			if (command == null) throw new ArgumentNullException("command");
			if (commandParameters != null)
			{
				foreach (SqlParameter p in commandParameters)
				{
					if (p != null)
					{
						// 检查未分配值的输出参数,将其分配以DBNull.Value. 
						if ((p.Direction == ParameterDirection.InputOutput || p.Direction == ParameterDirection.Input) &&
							(p.Value == null))
						{
							p.Value = DBNull.Value;
						}
						command.Parameters.Add(p);
					}
				}
			}
		}

		/// <summary> 
		/// 将DataRow类型的列值分配到SqlParameter参数数组. 
		/// </summary> 
		/// <param name="commandParameters">要分配值的SqlParameter参数数组</param> 
		/// <param name="dataRow">将要分配给存储过程参数的DataRow</param> 
		private static void AssignParameterValues(SqlParameter[] commandParameters, DataRow dataRow)
		{
			if ((commandParameters == null) || (dataRow == null))
			{
				return;
			}

			int i = 0;
			// 设置参数值 
			foreach (SqlParameter commandParameter in commandParameters)
			{
				// 创建参数名称,如果不存在,只抛出一个异常. 
				if (commandParameter.ParameterName == null ||
					commandParameter.ParameterName.Length <= 1)
					throw new Exception(
						string.Format("请提供参数{0}一个有效的名称{1}.", i, commandParameter.ParameterName));
				// 从dataRow的表中获取为参数数组中数组名称的列的索引. 
				// 如果存在和参数名称相同的列,则将列值赋给当前名称的参数. 
				if (dataRow.Table.Columns.IndexOf(commandParameter.ParameterName.Substring(1)) != -1)
					commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)];
				i++;
			}
		}

		/// <summary> 
		/// 将一个对象数组分配给SqlParameter参数数组. 
		/// </summary> 
		/// <param name="commandParameters">要分配值的SqlParameter参数数组</param> 
		/// <param name="parameterValues">将要分配给存储过程参数的对象数组</param> 
		private static void AssignParameterValues(SqlParameter[] commandParameters, object[] parameterValues)
		{
			if ((commandParameters == null) || (parameterValues == null))
			{
				return;
			}

			// 确保对象数组个数与参数个数匹配,如果不匹配,抛出一个异常. 
			if (commandParameters.Length != parameterValues.Length)
			{
				throw new ArgumentException("参数值个数与参数不匹配.");
			}

			// 给参数赋值 
			for (int i = 0, j = commandParameters.Length; i < j; i++)
			{
				// If the current array value derives from IDbDataParameter, then assign its Value property 
				if (parameterValues[i] is IDbDataParameter)
				{
					IDbDataParameter paramInstance = (IDbDataParameter)parameterValues[i];
					if (paramInstance.Value == null)
					{
						commandParameters[i].Value = DBNull.Value;
					}
					else
					{
						commandParameters[i].Value = paramInstance.Value;
					}
				}
				else if (parameterValues[i] == null)
				{
					commandParameters[i].Value = DBNull.Value;
				}
				else
				{
					commandParameters[i].Value = parameterValues[i];
				}
			}
		}

		/// <summary> 
		/// 预处理用户提供的命令,数据库连接/事务/命令类型/参数 
		/// </summary> 
		/// <param name="command">要处理的SqlCommand</param> 
		/// <param name="connection">数据库连接</param> 
		/// <param name="transaction">一个有效的事务或者是null值</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param> 
		/// <param name="commandText">存储过程名或都T-SQL命令文本</param> 
		/// <param name="commandParameters">和命令相关联的SqlParameter参数数组,如果没有参数为'null'</param> 
		/// <param name="mustCloseConnection"><c>true</c> 如果连接是打开的,则为true,其它情况下为false.</param> 
		private static void PrepareCommand(SqlCommand command, SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, out bool mustCloseConnection)
		{
			if (command == null) throw new ArgumentNullException("command");
			if (commandText == null || commandText.Length == 0) throw new ArgumentNullException("commandText");

			// If the provided connection is not open, we will open it 
			if (connection.State != ConnectionState.Open)
			{
				mustCloseConnection = true;
				connection.Open();
			}
			else
			{
				mustCloseConnection = false;
			}

			// 给命令分配一个数据库连接. 
			command.Connection = connection;

			// 设置命令文本(存储过程名或SQL语句) 
			command.CommandText = commandText;

			// 分配事务 
			if (transaction != null)
			{
				if (transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
				command.Transaction = transaction;
			}

			// 设置命令类型. 
			command.CommandType = commandType;

			// 分配命令参数 
			if (commandParameters != null)
			{
				AttachParameters(command, commandParameters);
			}
			return;
		}

		#endregion 私有构造函数和方法结束

		#region 数据库连接
		private static string _connectionString;
		/// <summary> 
		/// 一个有效的数据库连接字符串 
		/// </summary> 
		/// <returns></returns> 
		public static string GetConnSting()
		{
			if (string.IsNullOrEmpty(_connectionString))
			{
				_connectionString = ConfigurationManager.ConnectionStrings["randaoDBConnection"].ConnectionString;
			}
			return _connectionString;
		}
		/// <summary> 
		/// 一个有效的数据库连接对象 
		/// </summary> 
		/// <returns></returns> 
		public static SqlConnection GetConnection()
		{
			SqlConnection Connection = new SqlConnection(SqlHelper.GetConnSting());
			return Connection;
		}
		#endregion

		#region ExecuteNonQuery命令

		/// <summary> 
		/// 执行指定连接字符串,类型的SqlCommand. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders"); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param> 
		/// <param name="commandText">存储过程名称或SQL语句</param> 
		/// <returns>返回命令影响的行数</returns> 
		public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText)
		{
			return ExecuteNonQuery(connectionString, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// 执行指定连接字符串,类型的SqlCommand.如果没有提供参数,不返回结果. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param> 
		/// <param name="commandText">存储过程名称或SQL语句</param> 
		/// <param name="commandParameters">SqlParameter参数数组</param> 
		/// <returns>返回命令影响的行数</returns> 
		public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");

			using (SqlConnection connection = new SqlConnection(connectionString))
			{
				connection.Open();

				return ExecuteNonQuery(connection, commandType, commandText, commandParameters);
			}
		}

		/// <summary> 
		/// 执行指定连接字符串的存储过程,将对象数组的值赋给存储过程参数, 
		/// 此方法需要在参数缓存方法中探索参数并生成参数. 
		/// </summary> 
		/// <remarks> 
		/// 这个方法没有提供访问输出参数和返回值. 
		/// 示例:  
		///  int result = ExecuteNonQuery(connString, "PublishOrders", 24, 36); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串/param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="parameterValues">分配到存储过程输入参数的对象数组</param> 
		/// <returns>返回受影响的行数</returns> 
		public static int ExecuteNonQuery(string connectionString, string spName, params object[] parameterValues)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果存在参数值 
			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				// 从探索存储过程参数(加载到缓存)并分配给存储过程参数数组. 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

				// 给存储过程参数赋值 
				AssignParameterValues(commandParameters, parameterValues);

				return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				// 没有参数情况下 
				return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定数据库连接对象的命令 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders"); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <returns>返回影响的行数</returns> 
		public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText)
		{
			return ExecuteNonQuery(connection, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// 执行指定数据库连接对象的命令 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param> 
		/// <param name="commandText">T存储过程名称或T-SQL语句</param> 
		/// <param name="commandParameters">SqlParamter参数数组</param> 
		/// <returns>返回影响的行数</returns> 
		public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			if (connection == null) throw new ArgumentNullException("connection");

			// 创建SqlCommand命令,并进行预处理 
			SqlCommand cmd = new SqlCommand();
			bool mustCloseConnection = false;
			PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

			// Finally, execute the command 
			int retval = cmd.ExecuteNonQuery();

			// 清除参数,以便再次使用. 
			cmd.Parameters.Clear();
			if (mustCloseConnection)
				connection.Close();
			return retval;
		}

		/// <summary> 
		/// 执行指定数据库连接对象的命令,将对象数组的值赋给存储过程参数. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值 
		/// 示例:  
		///  int result = ExecuteNonQuery(conn, "PublishOrders", 24, 36); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名</param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		/// <returns>返回影响的行数</returns> 
		public static int ExecuteNonQuery(SqlConnection connection, string spName, params object[] parameterValues)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果有参数值 
			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				// 从缓存中加载存储过程参数 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

				// 给存储过程分配参数值 
				AssignParameterValues(commandParameters, parameterValues);

				return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行带事务的SqlCommand. 
		/// </summary> 
		/// <remarks> 
		/// 示例.:  
		///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders"); 
		/// </remarks> 
		/// <param name="transaction">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <returns>返回影响的行数/returns> 
		public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText)
		{
			return ExecuteNonQuery(transaction, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// 执行带事务的SqlCommand(指定参数). 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="transaction">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <param name="commandParameters">SqlParamter参数数组</param> 
		/// <returns>返回影响的行数</returns> 
		public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

			// 预处理 
			SqlCommand cmd = new SqlCommand();
			bool mustCloseConnection = false;
			PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

			// 执行 
			int retval = cmd.ExecuteNonQuery();

			// 清除参数集,以便再次使用. 
			cmd.Parameters.Clear();
			return retval;
		}

		/// <summary> 
		/// 执行带事务的SqlCommand(指定参数值). 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值 
		/// 示例:  
		///  int result = ExecuteNonQuery(conn, trans, "PublishOrders", 24, 36); 
		/// </remarks> 
		/// <param name="transaction">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名</param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		/// <returns>返回受影响的行数</returns> 
		public static int ExecuteNonQuery(SqlTransaction transaction, string spName, params object[] parameterValues)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果有参数值 
			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

				// 给存储过程参数赋值 
				AssignParameterValues(commandParameters, parameterValues);

				// 调用重载方法 
				return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				// 没有参数值 
				return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
			}
		}

		#endregion ExecuteNonQuery方法结束

		#region ExecuteDataset方法

		/// <summary> 
		/// 执行指定数据库连接字符串的命令,返回DataSet. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders"); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <returns>返回一个包含结果集的DataSet</returns> 
		public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText)
		{
			return ExecuteDataset(connectionString, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// 执行指定数据库连接字符串的命令,返回DataSet. 
		/// </summary> 
		/// <remarks> 
		/// 示例: 
		///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <param name="commandParameters">SqlParamters参数数组</param> 
		/// <returns>返回一个包含结果集的DataSet</returns> 
		public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");

			// 创建并打开数据库连接对象,操作完成释放对象. 
			using (SqlConnection connection = new SqlConnection(connectionString))
			{
				connection.Open();

				// 调用指定数据库连接字符串重载方法. 
				return ExecuteDataset(connection, commandType, commandText, commandParameters);
			}
		}

		/// <summary> 
		/// 执行指定数据库连接字符串的命令,直接提供参数值,返回DataSet. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值. 
		/// 示例: 
		///  DataSet ds = ExecuteDataset(connString, "GetOrders", 24, 36); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="spName">存储过程名</param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		/// <returns>返回一个包含结果集的DataSet</returns> 
		public static DataSet ExecuteDataset(string connectionString, string spName, params object[] parameterValues)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				// 从缓存中检索存储过程参数 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

				// 给存储过程参数分配值 
				AssignParameterValues(commandParameters, parameterValues);

				return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定数据库连接对象的命令,返回DataSet. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders"); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名或T-SQL语句</param> 
		/// <returns>返回一个包含结果集的DataSet</returns> 
		public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText)
		{
			return ExecuteDataset(connection, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// 执行指定数据库连接对象的命令,指定存储过程参数,返回DataSet. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名或T-SQL语句</param> 
		/// <param name="commandParameters">SqlParamter参数数组</param> 
		/// <returns>返回一个包含结果集的DataSet</returns> 
		public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			if (connection == null) throw new ArgumentNullException("connection");

			// 预处理 
			SqlCommand cmd = new SqlCommand();
			bool mustCloseConnection = false;
			PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

			// 创建SqlDataAdapter和DataSet. 
			using (SqlDataAdapter da = new SqlDataAdapter(cmd))
			{
				DataSet ds = new DataSet();

				// 填充DataSet. 
				da.Fill(ds);

				cmd.Parameters.Clear();

				if (mustCloseConnection)
					connection.Close();

				return ds;
			}
		}

		/// <summary> 
		/// 执行指定数据库连接对象的命令,指定参数值,返回DataSet. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输入参数和返回值. 
		/// 示例.:  
		///  DataSet ds = ExecuteDataset(conn, "GetOrders", 24, 36); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名</param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		/// <returns>返回一个包含结果集的DataSet</returns> 
		public static DataSet ExecuteDataset(SqlConnection connection, string spName, params object[] parameterValues)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				// 比缓存中加载存储过程参数 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

				// 给存储过程参数分配值 
				AssignParameterValues(commandParameters, parameterValues);

				return ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return ExecuteDataset(connection, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定事务的命令,返回DataSet. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders"); 
		/// </remarks> 
		/// <param name="transaction">事务</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名或T-SQL语句</param> 
		/// <returns>返回一个包含结果集的DataSet</returns> 
		public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText)
		{
			return ExecuteDataset(transaction, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// 执行指定事务的命令,指定参数,返回DataSet. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="transaction">事务</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名或T-SQL语句</param> 
		/// <param name="commandParameters">SqlParamter参数数组</param> 
		/// <returns>返回一个包含结果集的DataSet</returns> 
		public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

			// 预处理 
			SqlCommand cmd = new SqlCommand();
			bool mustCloseConnection = false;
			PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

			// 创建 DataAdapter & DataSet 
			using (SqlDataAdapter da = new SqlDataAdapter(cmd))
			{
				DataSet ds = new DataSet();
				da.Fill(ds);
				cmd.Parameters.Clear();
				return ds;
			}
		}

		/// <summary> 
		/// 执行指定事务的命令,指定参数值,返回DataSet. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输入参数和返回值. 
		/// 示例.:  
		///  DataSet ds = ExecuteDataset(trans, "GetOrders", 24, 36); 
		/// </remarks> 
		/// <param name="transaction">事务</param> 
		/// <param name="spName">存储过程名</param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		/// <returns>返回一个包含结果集的DataSet</returns> 
		public static DataSet ExecuteDataset(SqlTransaction transaction, string spName, params object[] parameterValues)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				// 从缓存中加载存储过程参数 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

				// 给存储过程参数分配值 
				AssignParameterValues(commandParameters, parameterValues);

				return ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
			}
		}

		#endregion ExecuteDataset数据集命令结束

		#region ExecuteReader 数据阅读器

		/// <summary> 
		/// 枚举,标识数据库连接是由SqlHelper提供还是由调用者提供 
		/// </summary> 
		private enum SqlConnectionOwnership
		{
			/// <summary>由SqlHelper提供连接</summary> 
			Internal,
			/// <summary>由调用者提供连接</summary> 
			External
		}

		/// <summary> 
		/// 执行指定数据库连接对象的数据阅读器. 
		/// </summary> 
		/// <remarks> 
		/// 如果是SqlHelper打开连接,当连接关闭DataReader也将关闭. 
		/// 如果是调用都打开连接,DataReader由调用都管理. 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="transaction">一个有效的事务,或者为 'null'</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名或T-SQL语句</param> 
		/// <param name="commandParameters">SqlParameters参数数组,如果没有参数则为'null'</param> 
		/// <param name="connectionOwnership">标识数据库连接对象是由调用者提供还是由SqlHelper提供</param> 
		/// <returns>返回包含结果集的SqlDataReader</returns> 
		private static SqlDataReader ExecuteReader(SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, SqlConnectionOwnership connectionOwnership)
		{
			if (connection == null) throw new ArgumentNullException("connection");

			bool mustCloseConnection = false;
			// 创建命令 
			SqlCommand cmd = new SqlCommand();
			try
			{
				PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

				// 创建数据阅读器 
				SqlDataReader dataReader;

				if (connectionOwnership == SqlConnectionOwnership.External)
				{
					dataReader = cmd.ExecuteReader();
				}
				else
				{
					dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
				}

				// 清除参数,以便再次使用.. 
				// HACK: There is a problem here, the output parameter values are fletched 
				// when the reader is closed, so if the parameters are detached from the command 
				// then the SqlReader can磘 set its values. 
				// When this happen, the parameters can磘 be used again in other command. 
				bool canClear = true;
				foreach (SqlParameter commandParameter in cmd.Parameters)
				{
					if (commandParameter.Direction != ParameterDirection.Input)
						canClear = false;
				}

				if (canClear)
				{
					cmd.Parameters.Clear();
				}

				return dataReader;
			}
			catch
			{
				if (mustCloseConnection)
					connection.Close();
				throw;
			}
		}

		/// <summary> 
		/// 执行指定数据库连接字符串的数据阅读器. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders"); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名或T-SQL语句</param> 
		/// <returns>返回包含结果集的SqlDataReader</returns> 
		public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)
		{
			return ExecuteReader(connectionString, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// 执行指定数据库连接字符串的数据阅读器,指定参数. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名或T-SQL语句</param> 
		/// <param name="commandParameters">SqlParamter参数数组(new SqlParameter("@prodid", 24))</param> 
		/// <returns>返回包含结果集的SqlDataReader</returns> 
		public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			SqlConnection connection = null;
			try
			{
				connection = new SqlConnection(connectionString);
				connection.Open();

				return ExecuteReader(connection, null, commandType, commandText, commandParameters, SqlConnectionOwnership.Internal);
			}
			catch
			{
				// If we fail to return the SqlDatReader, we need to close the connection ourselves 
				if (connection != null) connection.Close();
				throw;
			}

		}

		/// <summary> 
		/// 执行指定数据库连接字符串的数据阅读器,指定参数值. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值参数. 
		/// 示例:  
		///  SqlDataReader dr = ExecuteReader(connString, "GetOrders", 24, 36); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="spName">存储过程名</param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		/// <returns>返回包含结果集的SqlDataReader</returns> 
		public static SqlDataReader ExecuteReader(string connectionString, string spName, params object[] parameterValues)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

				AssignParameterValues(commandParameters, parameterValues);

				return ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定数据库连接对象的数据阅读器. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders"); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名或T-SQL语句</param> 
		/// <returns>返回包含结果集的SqlDataReader</returns> 
		public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText)
		{
			return ExecuteReader(connection, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// [调用者方式]执行指定数据库连接对象的数据阅读器,指定参数. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandParameters">SqlParamter参数数组</param> 
		/// <returns>返回包含结果集的SqlDataReader</returns> 
		public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			return ExecuteReader(connection, (SqlTransaction)null, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
		}

		/// <summary> 
		/// [调用者方式]执行指定数据库连接对象的数据阅读器,指定参数值. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值参数. 
		/// 示例:  
		///  SqlDataReader dr = ExecuteReader(conn, "GetOrders", 24, 36); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">T存储过程名</param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		/// <returns>返回包含结果集的SqlDataReader</returns> 
		public static SqlDataReader ExecuteReader(SqlConnection connection, string spName, params object[] parameterValues)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

				AssignParameterValues(commandParameters, parameterValues);

				return ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return ExecuteReader(connection, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// [调用者方式]执行指定数据库事务的数据阅读器,指定参数值. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders"); 
		/// </remarks> 
		/// <param name="transaction">一个有效的连接事务</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <returns>返回包含结果集的SqlDataReader</returns> 
		public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText)
		{
			return ExecuteReader(transaction, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// [调用者方式]执行指定数据库事务的数据阅读器,指定参数. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///   SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="transaction">一个有效的连接事务</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
		/// <returns>返回包含结果集的SqlDataReader</returns> 
		public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

			return ExecuteReader(transaction.Connection, transaction, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
		}

		/// <summary> 
		/// [调用者方式]执行指定数据库事务的数据阅读器,指定参数值. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值参数. 
		/// 
		/// 示例:  
		///  SqlDataReader dr = ExecuteReader(trans, "GetOrders", 24, 36); 
		/// </remarks> 
		/// <param name="transaction">一个有效的连接事务</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		/// <returns>返回包含结果集的SqlDataReader</returns> 
		public static SqlDataReader ExecuteReader(SqlTransaction transaction, string spName, params object[] parameterValues)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果有参数值 
			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

				AssignParameterValues(commandParameters, parameterValues);

				return ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				// 没有参数值 
				return ExecuteReader(transaction, CommandType.StoredProcedure, spName);
			}
		}

		#endregion ExecuteReader数据阅读器

		#region ExecuteScalar 返回结果集中的第一行第一列

		/// <summary> 
		/// 执行指定数据库连接字符串的命令,返回结果集中的第一行第一列. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount"); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <returns>返回结果集中的第一行第一列</returns> 
		public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText)
		{
			// 执行参数为空的方法 
			return ExecuteScalar(connectionString, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// 执行指定数据库连接字符串的命令,指定参数,返回结果集中的第一行第一列. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
		/// <returns>返回结果集中的第一行第一列</returns> 
		public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			// 创建并打开数据库连接对象,操作完成释放对象. 
			using (SqlConnection connection = new SqlConnection(connectionString))
			{
				connection.Open();

				// 调用指定数据库连接字符串重载方法. 
				return ExecuteScalar(connection, commandType, commandText, commandParameters);
			}
		}

		/// <summary> 
		/// 执行指定数据库连接字符串的命令,指定参数值,返回结果集中的第一行第一列. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值参数. 
		/// 
		/// 示例:  
		///  int orderCount = (int)ExecuteScalar(connString, "GetOrderCount", 24, 36); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		/// <returns>返回结果集中的第一行第一列</returns> 
		public static object ExecuteScalar(string connectionString, string spName, params object[] parameterValues)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果有参数值 
			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

				// 给存储过程参数赋值 
				AssignParameterValues(commandParameters, parameterValues);

				// 调用重载方法 
				return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				// 没有参数值 
				return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定数据库连接对象的命令,返回结果集中的第一行第一列. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount"); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <returns>返回结果集中的第一行第一列</returns> 
		public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText)
		{
			// 执行参数为空的方法 
			return ExecuteScalar(connection, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// 执行指定数据库连接对象的命令,指定参数,返回结果集中的第一行第一列. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
		/// <returns>返回结果集中的第一行第一列</returns> 
		public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			if (connection == null) throw new ArgumentNullException("connection");

			// 创建SqlCommand命令,并进行预处理 
			SqlCommand cmd = new SqlCommand();

			bool mustCloseConnection = false;
			PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

			// 执行SqlCommand命令,并返回结果. 
			object retval = cmd.ExecuteScalar();

			// 清除参数,以便再次使用. 
			cmd.Parameters.Clear();

			if (mustCloseConnection)
				connection.Close();

			return retval;
		}

		/// <summary> 
		/// 执行指定数据库连接对象的命令,指定参数值,返回结果集中的第一行第一列. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值参数. 
		/// 
		/// 示例:  
		///  int orderCount = (int)ExecuteScalar(conn, "GetOrderCount", 24, 36); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		/// <returns>返回结果集中的第一行第一列</returns> 
		public static object ExecuteScalar(SqlConnection connection, string spName, params object[] parameterValues)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果有参数值 
			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

				// 给存储过程参数赋值 
				AssignParameterValues(commandParameters, parameterValues);

				// 调用重载方法 
				return ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				// 没有参数值 
				return ExecuteScalar(connection, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定数据库事务的命令,返回结果集中的第一行第一列. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount"); 
		/// </remarks> 
		/// <param name="transaction">一个有效的连接事务</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <returns>返回结果集中的第一行第一列</returns> 
		public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText)
		{
			// 执行参数为空的方法 
			return ExecuteScalar(transaction, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// 执行指定数据库事务的命令,指定参数,返回结果集中的第一行第一列. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="transaction">一个有效的连接事务</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
		/// <returns>返回结果集中的第一行第一列</returns> 
		public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

			// 创建SqlCommand命令,并进行预处理 
			SqlCommand cmd = new SqlCommand();
			bool mustCloseConnection = false;
			PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

			// 执行SqlCommand命令,并返回结果. 
			object retval = cmd.ExecuteScalar();

			// 清除参数,以便再次使用. 
			cmd.Parameters.Clear();
			return retval;
		}

		/// <summary> 
		/// 执行指定数据库事务的命令,指定参数值,返回结果集中的第一行第一列. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值参数. 
		/// 
		/// 示例:  
		///  int orderCount = (int)ExecuteScalar(trans, "GetOrderCount", 24, 36); 
		/// </remarks> 
		/// <param name="transaction">一个有效的连接事务</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		/// <returns>返回结果集中的第一行第一列</returns> 
		public static object ExecuteScalar(SqlTransaction transaction, string spName, params object[] parameterValues)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果有参数值 
			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				// PPull the parameters for this stored procedure from the parameter cache () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

				// 给存储过程参数赋值 
				AssignParameterValues(commandParameters, parameterValues);

				// 调用重载方法 
				return ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				// 没有参数值 
				return ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
			}
		}

		#endregion ExecuteScalar

		#region ExecuteXmlReader XML阅读器
		/// <summary> 
		/// 执行指定数据库连接对象的SqlCommand命令,并产生一个XmlReader对象做为结果集返回. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders"); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句 using "FOR XML AUTO"</param> 
		/// <returns>返回XmlReader结果集对象.</returns> 
		public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText)
		{
			// 执行参数为空的方法 
			return ExecuteXmlReader(connection, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// 执行指定数据库连接对象的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句 using "FOR XML AUTO"</param> 
		/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
		/// <returns>返回XmlReader结果集对象.</returns> 
		public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			if (connection == null) throw new ArgumentNullException("connection");

			bool mustCloseConnection = false;
			// 创建SqlCommand命令,并进行预处理 
			SqlCommand cmd = new SqlCommand();
			try
			{
				PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

				// 执行命令 
				XmlReader retval = cmd.ExecuteXmlReader();

				// 清除参数,以便再次使用. 
				cmd.Parameters.Clear();

				return retval;
			}
			catch
			{
				if (mustCloseConnection)
					connection.Close();
				throw;
			}
		}

		/// <summary> 
		/// 执行指定数据库连接对象的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数值. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值参数. 
		/// 
		/// 示例:  
		///  XmlReader r = ExecuteXmlReader(conn, "GetOrders", 24, 36); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名称 using "FOR XML AUTO"</param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		/// <returns>返回XmlReader结果集对象.</returns> 
		public static XmlReader ExecuteXmlReader(SqlConnection connection, string spName, params object[] parameterValues)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果有参数值 
			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

				// 给存储过程参数赋值 
				AssignParameterValues(commandParameters, parameterValues);

				// 调用重载方法 
				return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				// 没有参数值 
				return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定数据库事务的SqlCommand命令,并产生一个XmlReader对象做为结果集返回. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders"); 
		/// </remarks> 
		/// <param name="transaction">一个有效的连接事务</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句 using "FOR XML AUTO"</param> 
		/// <returns>返回XmlReader结果集对象.</returns> 
		public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText)
		{
			// 执行参数为空的方法 
			return ExecuteXmlReader(transaction, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary> 
		/// 执行指定数据库事务的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="transaction">一个有效的连接事务</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句 using "FOR XML AUTO"</param> 
		/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
		/// <returns>返回XmlReader结果集对象.</returns> 
		public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

			// 创建SqlCommand命令,并进行预处理 
			SqlCommand cmd = new SqlCommand();
			bool mustCloseConnection = false;
			PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

			// 执行命令 
			XmlReader retval = cmd.ExecuteXmlReader();

			// 清除参数,以便再次使用. 
			cmd.Parameters.Clear();
			return retval;
		}

		/// <summary> 
		/// 执行指定数据库事务的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数值. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值参数. 
		/// 
		/// 示例:  
		///  XmlReader r = ExecuteXmlReader(trans, "GetOrders", 24, 36); 
		/// </remarks> 
		/// <param name="transaction">一个有效的连接事务</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		/// <returns>返回一个包含结果集的DataSet.</returns> 
		public static XmlReader ExecuteXmlReader(SqlTransaction transaction, string spName, params object[] parameterValues)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果有参数值 
			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

				// 给存储过程参数赋值 
				AssignParameterValues(commandParameters, parameterValues);

				// 调用重载方法 
				return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				// 没有参数值 
				return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
			}
		}

		#endregion ExecuteXmlReader 阅读器结束

		#region FillDataset 填充数据集
		/// <summary> 
		/// 执行指定数据库连接字符串的命令,映射数据表并填充数据集. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <param name="dataSet">要填充结果集的DataSet实例</param> 
		/// <param name="tableNames">表映射的数据表数组 
		/// 用户定义的表名 (可有是实际的表名.)</param> 
		public static void FillDataset(string connectionString, CommandType commandType, string commandText, DataSet dataSet, string[] tableNames)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (dataSet == null) throw new ArgumentNullException("dataSet");

			// 创建并打开数据库连接对象,操作完成释放对象. 
			using (SqlConnection connection = new SqlConnection(connectionString))
			{
				connection.Open();

				// 调用指定数据库连接字符串重载方法. 
				FillDataset(connection, commandType, commandText, dataSet, tableNames);
			}
		}

		/// <summary> 
		/// 执行指定数据库连接字符串的命令,映射数据表并填充数据集.指定命令参数. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
		/// <param name="dataSet">要填充结果集的DataSet实例</param> 
		/// <param name="tableNames">表映射的数据表数组 
		/// 用户定义的表名 (可有是实际的表名.) 
		/// </param> 
		public static void FillDataset(string connectionString, CommandType commandType,
			string commandText, DataSet dataSet, string[] tableNames,
			params SqlParameter[] commandParameters)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (dataSet == null) throw new ArgumentNullException("dataSet");
			// 创建并打开数据库连接对象,操作完成释放对象. 
			using (SqlConnection connection = new SqlConnection(connectionString))
			{
				connection.Open();

				// 调用指定数据库连接字符串重载方法. 
				FillDataset(connection, commandType, commandText, dataSet, tableNames, commandParameters);
			}
		}

		/// <summary> 
		/// 执行指定数据库连接字符串的命令,映射数据表并填充数据集,指定存储过程参数值. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值参数. 
		/// 
		/// 示例:  
		///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, 24); 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataSet">要填充结果集的DataSet实例</param> 
		/// <param name="tableNames">表映射的数据表数组 
		/// 用户定义的表名 (可有是实际的表名.) 
		/// </param>    
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		public static void FillDataset(string connectionString, string spName,
			DataSet dataSet, string[] tableNames,
			params object[] parameterValues)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (dataSet == null) throw new ArgumentNullException("dataSet");
			// 创建并打开数据库连接对象,操作完成释放对象. 
			using (SqlConnection connection = new SqlConnection(connectionString))
			{
				connection.Open();

				// 调用指定数据库连接字符串重载方法. 
				FillDataset(connection, spName, dataSet, tableNames, parameterValues);
			}
		}

		/// <summary> 
		/// 执行指定数据库连接对象的命令,映射数据表并填充数据集. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <param name="dataSet">要填充结果集的DataSet实例</param> 
		/// <param name="tableNames">表映射的数据表数组 
		/// 用户定义的表名 (可有是实际的表名.) 
		/// </param>    
		public static void FillDataset(SqlConnection connection, CommandType commandType,
			string commandText, DataSet dataSet, string[] tableNames)
		{
			FillDataset(connection, commandType, commandText, dataSet, tableNames, null);
		}

		/// <summary> 
		/// 执行指定数据库连接对象的命令,映射数据表并填充数据集,指定参数. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <param name="dataSet">要填充结果集的DataSet实例</param> 
		/// <param name="tableNames">表映射的数据表数组 
		/// 用户定义的表名 (可有是实际的表名.) 
		/// </param> 
		/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
		public static void FillDataset(SqlConnection connection, CommandType commandType,
			string commandText, DataSet dataSet, string[] tableNames,
			params SqlParameter[] commandParameters)
		{
			FillDataset(connection, null, commandType, commandText, dataSet, tableNames, commandParameters);
		}

		/// <summary> 
		/// 执行指定数据库连接对象的命令,映射数据表并填充数据集,指定存储过程参数值. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值参数. 
		/// 
		/// 示例:  
		///  FillDataset(conn, "GetOrders", ds, new string[] {"orders"}, 24, 36); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataSet">要填充结果集的DataSet实例</param> 
		/// <param name="tableNames">表映射的数据表数组 
		/// 用户定义的表名 (可有是实际的表名.) 
		/// </param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		public static void FillDataset(SqlConnection connection, string spName,
			DataSet dataSet, string[] tableNames,
			params object[] parameterValues)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (dataSet == null) throw new ArgumentNullException("dataSet");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果有参数值 
			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

				// 给存储过程参数赋值 
				AssignParameterValues(commandParameters, parameterValues);

				// 调用重载方法 
				FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
			}
			else
			{
				// 没有参数值 
				FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames);
			}
		}

		/// <summary> 
		/// 执行指定数据库事务的命令,映射数据表并填充数据集. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}); 
		/// </remarks> 
		/// <param name="transaction">一个有效的连接事务</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <param name="dataSet">要填充结果集的DataSet实例</param> 
		/// <param name="tableNames">表映射的数据表数组 
		/// 用户定义的表名 (可有是实际的表名.) 
		/// </param> 
		public static void FillDataset(SqlTransaction transaction, CommandType commandType,
			string commandText,
			DataSet dataSet, string[] tableNames)
		{
			FillDataset(transaction, commandType, commandText, dataSet, tableNames, null);
		}

		/// <summary> 
		/// 执行指定数据库事务的命令,映射数据表并填充数据集,指定参数. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="transaction">一个有效的连接事务</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <param name="dataSet">要填充结果集的DataSet实例</param> 
		/// <param name="tableNames">表映射的数据表数组 
		/// 用户定义的表名 (可有是实际的表名.) 
		/// </param> 
		/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
		public static void FillDataset(SqlTransaction transaction, CommandType commandType,
			string commandText, DataSet dataSet, string[] tableNames,
			params SqlParameter[] commandParameters)
		{
			FillDataset(transaction.Connection, transaction, commandType, commandText, dataSet, tableNames, commandParameters);
		}

		/// <summary> 
		/// 执行指定数据库事务的命令,映射数据表并填充数据集,指定存储过程参数值. 
		/// </summary> 
		/// <remarks> 
		/// 此方法不提供访问存储过程输出参数和返回值参数. 
		/// 
		/// 示例:  
		///  FillDataset(trans, "GetOrders", ds, new string[]{"orders"}, 24, 36); 
		/// </remarks> 
		/// <param name="transaction">一个有效的连接事务</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataSet">要填充结果集的DataSet实例</param> 
		/// <param name="tableNames">表映射的数据表数组 
		/// 用户定义的表名 (可有是实际的表名.) 
		/// </param> 
		/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
		public static void FillDataset(SqlTransaction transaction, string spName,
			DataSet dataSet, string[] tableNames,
			params object[] parameterValues)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
			if (dataSet == null) throw new ArgumentNullException("dataSet");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果有参数值 
			if ((parameterValues != null) && (parameterValues.Length > 0))
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

				// 给存储过程参数赋值 
				AssignParameterValues(commandParameters, parameterValues);

				// 调用重载方法 
				FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
			}
			else
			{
				// 没有参数值 
				FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames);
			}
		}

		/// <summary> 
		/// [私有方法][内部调用]执行指定数据库连接对象/事务的命令,映射数据表并填充数据集,DataSet/TableNames/SqlParameters. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  FillDataset(conn, trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24)); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="transaction">一个有效的连接事务</param> 
		/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
		/// <param name="commandText">存储过程名称或T-SQL语句</param> 
		/// <param name="dataSet">要填充结果集的DataSet实例</param> 
		/// <param name="tableNames">表映射的数据表数组 
		/// 用户定义的表名 (可有是实际的表名.) 
		/// </param> 
		/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
		private static void FillDataset(SqlConnection connection, SqlTransaction transaction, CommandType commandType,
			string commandText, DataSet dataSet, string[] tableNames,
			params SqlParameter[] commandParameters)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (dataSet == null) throw new ArgumentNullException("dataSet");

			// 创建SqlCommand命令,并进行预处理 
			SqlCommand command = new SqlCommand();
			bool mustCloseConnection = false;
			PrepareCommand(command, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

			// 执行命令 
			using (SqlDataAdapter dataAdapter = new SqlDataAdapter(command))
			{

				// 追加表映射 
				if (tableNames != null && tableNames.Length > 0)
				{
					string tableName = "Table";
					for (int index = 0; index < tableNames.Length; index++)
					{
						if (tableNames[index] == null || tableNames[index].Length == 0) throw new ArgumentException("The tableNames parameter must contain a list of tables, a value was provided as null or empty string.", "tableNames");
						dataAdapter.TableMappings.Add(tableName, tableNames[index]);
						tableName += (index + 1).ToString();
					}
				}

				// 填充数据集使用默认表名称 
				dataAdapter.Fill(dataSet);

				// 清除参数,以便再次使用. 
				command.Parameters.Clear();
			}

			if (mustCloseConnection)
				connection.Close();
		}
		#endregion

		#region UpdateDataset 更新数据集
		/// <summary> 
		/// 执行数据集更新到数据库,指定inserted, updated, or deleted命令. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  UpdateDataset(conn, insertCommand, deleteCommand, updateCommand, dataSet, "Order"); 
		/// </remarks> 
		/// <param name="insertCommand">[追加记录]一个有效的T-SQL语句或存储过程</param> 
		/// <param name="deleteCommand">[删除记录]一个有效的T-SQL语句或存储过程</param> 
		/// <param name="updateCommand">[更新记录]一个有效的T-SQL语句或存储过程</param> 
		/// <param name="dataSet">要更新到数据库的DataSet</param> 
		/// <param name="tableName">要更新到数据库的DataTable</param> 
		public static void UpdateDataset(SqlCommand insertCommand, SqlCommand deleteCommand, SqlCommand updateCommand, DataSet dataSet, string tableName)
		{
			if (insertCommand == null) throw new ArgumentNullException("insertCommand");
			if (deleteCommand == null) throw new ArgumentNullException("deleteCommand");
			if (updateCommand == null) throw new ArgumentNullException("updateCommand");
			if (tableName == null || tableName.Length == 0) throw new ArgumentNullException("tableName");

			// 创建SqlDataAdapter,当操作完成后释放. 
			using (SqlDataAdapter dataAdapter = new SqlDataAdapter())
			{
				// 设置数据适配器命令 
				dataAdapter.UpdateCommand = updateCommand;
				dataAdapter.InsertCommand = insertCommand;
				dataAdapter.DeleteCommand = deleteCommand;

				// 更新数据集改变到数据库 
				dataAdapter.Update(dataSet, tableName);

				// 提交所有改变到数据集. 
				dataSet.AcceptChanges();
			}
		}
		#endregion

		#region CreateCommand 创建一条SqlCommand命令
		/// <summary> 
		/// 创建SqlCommand命令,指定数据库连接对象,存储过程名和参数. 
		/// </summary> 
		/// <remarks> 
		/// 示例:  
		///  SqlCommand command = CreateCommand(conn, "AddCustomer", "CustomerID", "CustomerName"); 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="sourceColumns">源表的列名称数组</param> 
		/// <returns>返回SqlCommand命令</returns> 
		public static SqlCommand CreateCommand(SqlConnection connection, string spName, params string[] sourceColumns)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 创建命令 
			SqlCommand cmd = new SqlCommand(spName, connection);
			cmd.CommandType = CommandType.StoredProcedure;

			// 如果有参数值 
			if ((sourceColumns != null) && (sourceColumns.Length > 0))
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

				// 将源表的列到映射到DataSet命令中. 
				for (int index = 0; index < sourceColumns.Length; index++)
					commandParameters[index].SourceColumn = sourceColumns[index];

				// Attach the discovered parameters to the SqlCommand object 
				AttachParameters(cmd, commandParameters);
			}

			return cmd;
		}
		#endregion

		#region ExecuteNonQueryTypedParams 类型化参数(DataRow)
		/// <summary> 
		/// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回受影响的行数. 
		/// </summary> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回影响的行数</returns> 
		public static int ExecuteNonQueryTypedParams(String connectionString, String spName, DataRow dataRow)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果row有值,存储过程必须初始化. 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回受影响的行数. 
		/// </summary> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回影响的行数</returns> 
		public static int ExecuteNonQueryTypedParams(SqlConnection connection, String spName, DataRow dataRow)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果row有值,存储过程必须初始化. 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定连接数据库事物的存储过程,使用DataRow做为参数值,返回受影响的行数. 
		/// </summary> 
		/// <param name="transaction">一个有效的连接事务 object</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回影响的行数</returns> 
		public static int ExecuteNonQueryTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// Sf the row has values, the store procedure parameters must be initialized 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
			}
		}
		#endregion

		#region ExecuteDatasetTypedParams 类型化参数(DataRow)
		/// <summary> 
		/// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回DataSet. 
		/// </summary> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回一个包含结果集的DataSet.</returns> 
		public static DataSet ExecuteDatasetTypedParams(string connectionString, String spName, DataRow dataRow)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			//如果row有值,存储过程必须初始化. 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回DataSet. 
		/// </summary> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回一个包含结果集的DataSet.</returns> 
		/// 
		public static DataSet ExecuteDatasetTypedParams(SqlConnection connection, String spName, DataRow dataRow)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果row有值,存储过程必须初始化. 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定连接数据库事务的存储过程,使用DataRow做为参数值,返回DataSet. 
		/// </summary> 
		/// <param name="transaction">一个有效的连接事务 object</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回一个包含结果集的DataSet.</returns> 
		public static DataSet ExecuteDatasetTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果row有值,存储过程必须初始化. 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
			}
		}

		#endregion

		#region ExecuteReaderTypedParams 类型化参数(DataRow)
		/// <summary> 
		/// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回DataReader. 
		/// </summary> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回包含结果集的SqlDataReader</returns> 
		public static SqlDataReader ExecuteReaderTypedParams(String connectionString, String spName, DataRow dataRow)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果row有值,存储过程必须初始化. 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
			}
		}


		/// <summary> 
		/// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回DataReader. 
		/// </summary> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回包含结果集的SqlDataReader</returns> 
		public static SqlDataReader ExecuteReaderTypedParams(SqlConnection connection, String spName, DataRow dataRow)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果row有值,存储过程必须初始化. 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定连接数据库事物的存储过程,使用DataRow做为参数值,返回DataReader. 
		/// </summary> 
		/// <param name="transaction">一个有效的连接事务 object</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回包含结果集的SqlDataReader</returns> 
		public static SqlDataReader ExecuteReaderTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果row有值,存储过程必须初始化. 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName);
			}
		}
		#endregion

		#region ExecuteScalarTypedParams 类型化参数(DataRow)
		/// <summary> 
		/// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回结果集中的第一行第一列. 
		/// </summary> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回结果集中的第一行第一列</returns> 
		public static object ExecuteScalarTypedParams(String connectionString, String spName, DataRow dataRow)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果row有值,存储过程必须初始化. 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回结果集中的第一行第一列. 
		/// </summary> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回结果集中的第一行第一列</returns> 
		public static object ExecuteScalarTypedParams(SqlConnection connection, String spName, DataRow dataRow)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果row有值,存储过程必须初始化. 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定连接数据库事务的存储过程,使用DataRow做为参数值,返回结果集中的第一行第一列. 
		/// </summary> 
		/// <param name="transaction">一个有效的连接事务 object</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回结果集中的第一行第一列</returns> 
		public static object ExecuteScalarTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果row有值,存储过程必须初始化. 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
			}
		}
		#endregion

		#region ExecuteXmlReaderTypedParams 类型化参数(DataRow)
		/// <summary> 
		/// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回XmlReader类型的结果集. 
		/// </summary> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回XmlReader结果集对象.</returns> 
		public static XmlReader ExecuteXmlReaderTypedParams(SqlConnection connection, String spName, DataRow dataRow)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果row有值,存储过程必须初始化. 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary> 
		/// 执行指定连接数据库事务的存储过程,使用DataRow做为参数值,返回XmlReader类型的结果集. 
		/// </summary> 
		/// <param name="transaction">一个有效的连接事务 object</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="dataRow">使用DataRow作为参数值</param> 
		/// <returns>返回XmlReader结果集对象.</returns> 
		public static XmlReader ExecuteXmlReaderTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
		{
			if (transaction == null) throw new ArgumentNullException("transaction");
			if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			// 如果row有值,存储过程必须初始化. 
			if (dataRow != null && dataRow.ItemArray.Length > 0)
			{
				// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

				// 分配参数值 
				AssignParameterValues(commandParameters, dataRow);

				return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
			else
			{
				return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
			}
		}
		#endregion

	}

	/// <summary> 
	/// SqlHelperParameterCache提供缓存存储过程参数,并能够在运行时从存储过程中探索参数. 
	/// </summary> 
	public sealed class SqlHelperParameterCache
	{
		#region 私有方法,字段,构造函数
		// 私有构造函数,妨止类被实例化. 
		private SqlHelperParameterCache() { }

		// 这个方法要注意 
		private static Hashtable paramCache = Hashtable.Synchronized(new Hashtable());

		/// <summary> 
		/// 探索运行时的存储过程,返回SqlParameter参数数组. 
		/// 初始化参数值为 DBNull.Value. 
		/// </summary> 
		/// <param name="connection">一个有效的数据库连接</param> 
		/// <param name="spName">存储过程名称</param> 
		/// <param name="includeReturnValueParameter">是否包含返回值参数</param> 
		/// <returns>返回SqlParameter参数数组</returns> 
		private static SqlParameter[] DiscoverSpParameterSet(SqlConnection connection, string spName, bool includeReturnValueParameter)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			SqlCommand cmd = new SqlCommand(spName, connection);
			cmd.CommandType = CommandType.StoredProcedure;

			connection.Open();
			// 检索cmd指定的存储过程的参数信息,并填充到cmd的Parameters参数集中. 
			SqlCommandBuilder.DeriveParameters(cmd);
			connection.Close();
			// 如果不包含返回值参数,将参数集中的每一个参数删除. 
			if (!includeReturnValueParameter)
			{
				cmd.Parameters.RemoveAt(0);
			}

			// 创建参数数组 
			SqlParameter[] discoveredParameters = new SqlParameter[cmd.Parameters.Count];
			// 将cmd的Parameters参数集复制到discoveredParameters数组. 
			cmd.Parameters.CopyTo(discoveredParameters, 0);

			// 初始化参数值为 DBNull.Value. 
			foreach (SqlParameter discoveredParameter in discoveredParameters)
			{
				discoveredParameter.Value = DBNull.Value;
			}
			return discoveredParameters;
		}

		/// <summary> 
		/// SqlParameter参数数组的深层拷贝. 
		/// </summary> 
		/// <param name="originalParameters">原始参数数组</param> 
		/// <returns>返回一个同样的参数数组</returns> 
		private static SqlParameter[] CloneParameters(SqlParameter[] originalParameters)
		{
			SqlParameter[] clonedParameters = new SqlParameter[originalParameters.Length];

			for (int i = 0, j = originalParameters.Length; i < j; i++)
			{
				clonedParameters[i] = (SqlParameter)((ICloneable)originalParameters[i]).Clone();
			}

			return clonedParameters;
		}

		#endregion 私有方法,字段,构造函数结束

		#region 缓存方法

		/// <summary> 
		/// 追加参数数组到缓存. 
		/// </summary> 
		/// <param name="connectionString">一个有效的数据库连接字符串</param> 
		/// <param name="commandText">存储过程名或SQL语句</param> 
		/// <param name="commandParameters">要缓存的参数数组</param> 
		public static void CacheParameterSet(string connectionString, string commandText, params SqlParameter[] commandParameters)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (commandText == null || commandText.Length == 0) throw new ArgumentNullException("commandText");

			string hashKey = connectionString + ":" + commandText;

			paramCache[hashKey] = commandParameters;
		}

		/// <summary> 
		/// 从缓存中获取参数数组. 
		/// </summary> 
		/// <param name="connectionString">一个有效的数据库连接字符</param> 
		/// <param name="commandText">存储过程名或SQL语句</param> 
		/// <returns>参数数组</returns> 
		public static SqlParameter[] GetCachedParameterSet(string connectionString, string commandText)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (commandText == null || commandText.Length == 0) throw new ArgumentNullException("commandText");

			string hashKey = connectionString + ":" + commandText;

			SqlParameter[] cachedParameters = paramCache[hashKey] as SqlParameter[];
			if (cachedParameters == null)
			{
				return null;
			}
			else
			{
				return CloneParameters(cachedParameters);
			}
		}

		#endregion 缓存方法结束

		#region 检索指定的存储过程的参数集

		/// <summary> 
		/// 返回指定的存储过程的参数集 
		/// </summary> 
		/// <remarks> 
		/// 这个方法将查询数据库,并将信息存储到缓存. 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符</param> 
		/// <param name="spName">存储过程名</param> 
		/// <returns>返回SqlParameter参数数组</returns> 
		public static SqlParameter[] GetSpParameterSet(string connectionString, string spName)
		{
			return GetSpParameterSet(connectionString, spName, false);
		}

		/// <summary> 
		/// 返回指定的存储过程的参数集 
		/// </summary> 
		/// <remarks> 
		/// 这个方法将查询数据库,并将信息存储到缓存. 
		/// </remarks> 
		/// <param name="connectionString">一个有效的数据库连接字符.</param> 
		/// <param name="spName">存储过程名</param> 
		/// <param name="includeReturnValueParameter">是否包含返回值参数</param> 
		/// <returns>返回SqlParameter参数数组</returns> 
		public static SqlParameter[] GetSpParameterSet(string connectionString, string spName, bool includeReturnValueParameter)
		{
			if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			using (SqlConnection connection = new SqlConnection(connectionString))
			{
				return GetSpParameterSetInternal(connection, spName, includeReturnValueParameter);
			}
		}

		/// <summary> 
		/// [内部]返回指定的存储过程的参数集(使用连接对象). 
		/// </summary> 
		/// <remarks> 
		/// 这个方法将查询数据库,并将信息存储到缓存. 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接字符</param> 
		/// <param name="spName">存储过程名</param> 
		/// <returns>返回SqlParameter参数数组</returns> 
		internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName)
		{
			return GetSpParameterSet(connection, spName, false);
		}

		/// <summary> 
		/// [内部]返回指定的存储过程的参数集(使用连接对象) 
		/// </summary> 
		/// <remarks> 
		/// 这个方法将查询数据库,并将信息存储到缓存. 
		/// </remarks> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名</param> 
		/// <param name="includeReturnValueParameter"> 
		/// 是否包含返回值参数 
		/// </param> 
		/// <returns>返回SqlParameter参数数组</returns> 
		internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName, bool includeReturnValueParameter)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			using (SqlConnection clonedConnection = (SqlConnection)((ICloneable)connection).Clone())
			{
				return GetSpParameterSetInternal(clonedConnection, spName, includeReturnValueParameter);
			}
		}

		/// <summary> 
		/// [私有]返回指定的存储过程的参数集(使用连接对象) 
		/// </summary> 
		/// <param name="connection">一个有效的数据库连接对象</param> 
		/// <param name="spName">存储过程名</param> 
		/// <param name="includeReturnValueParameter">是否包含返回值参数</param> 
		/// <returns>返回SqlParameter参数数组</returns> 
		private static SqlParameter[] GetSpParameterSetInternal(SqlConnection connection, string spName, bool includeReturnValueParameter)
		{
			if (connection == null) throw new ArgumentNullException("connection");
			if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

			string hashKey = connection.ConnectionString + ":" + spName + (includeReturnValueParameter ? ":include ReturnValue Parameter" : "");

			SqlParameter[] cachedParameters;

			cachedParameters = paramCache[hashKey] as SqlParameter[];
			if (cachedParameters == null)
			{
				SqlParameter[] spParameters = DiscoverSpParameterSet(connection, spName, includeReturnValueParameter);
				paramCache[hashKey] = spParameters;
				cachedParameters = spParameters;
			}

			return CloneParameters(cachedParameters);
		}

		#endregion 参数集检索结束

	}
}